only a fraction of the costs of supporting themóclash with a badly organized majority, the members of which have only moderate objections to the relatively small extra costs imposed upon them by the fertility decisions of the minority. The children, of course, represent a completely disfranchised block, powerless to influence actions that affect their vital interests. The parents may act selfishly or may be simply ignorant of the disadvantages imposed upon their existing children by additional siblings.
Negative Social Effects of High Fertility. Negative externalities consequent upon high fertility pose, of course, much higher-order difficulties within the society as a whole. (One may add that there are analogous difficulties within the society of nations as well, a topic seldom touched upon in the literature.) A nonexhaustive list of these may single out three broad types of effects: undesired consequences of parental decision falling on (a) all other members of the society (as with pollution); (b) affecting some special classes of people (e.g., those whose livelihood is derived from wages only or those paying taxes); and (c) disadvantaging the young generation or, in general, the subsequent generations. As the negative effects are likely to be widely distributed, the possibility of bargaining and arranging for compensatory payments between individual families, and thereby moving toward an optimum, is practically nil. Neither will mere information about the existence of externalities change the behavior from which externalities originate: rational parents will correctly perceive that the effects of their actions on any particular family or on society as a whole are infinitesimally small.
The only workable approach would seem to be governmental intervention seeking to discourage fertility whenever it is found that the social costs of a marginal birth exceed marginal private benefits. Such intervention may take the form of outright coercion; or preferably, an appropriate set of economic incentives or disincentives may be applied to induce socially desirable behavior. It should be recognized, however, that the guidance economists are at present able to give for policymakers on such matters is less than solid. The extremely diffuse nature of the externalities involved; the fact that many of these externalities will manifest themselves through not easily traceable changes in the relative prices of factors and of outputs; the problem of taking into account the numerous positive externalities enjoyed by various segments of the society; the problem of considering the equity of the existing income distribution; the problem of weighing long-term effects against short-term consequences; and the necessity to introduce the intergenerational welfare considerations: all these problems make the applicability of cost-benefit analysis for policy decisions extremely restricted. These difficulties are compounded by the necessity to attach a cost measure to the corrective policy itself: a matter involving complex political, moral, and cultural considerations besides the often considerable purely economic costs.